Clearance-cutting machinery for twist-drills



(No Model.)

0. PARPART.

CLEARANCE CUTTING MACHINERY FOR TWIST DB ILLS. No. 488,218. PatentedDec. 20, 1892.

WH'QQQWQS "w KNEW ll'n'irnn STATES Parent much.

OTTO PARPART, OF AKRON, OHIO.

CLEARANCE-CUTTING MACHINERY FOR TWIST -DRILLS.

SPECIFICATION forming part of Letters Patent No; 488,218, dated December20, 1892.

Application filed December 14, 1891. Serial No. 414,997. (No model.)

To all whom it may concern.-

Be it known that I, 013230 PARPART, a citizen of the United States,residing at Akron, in the county of Summit and State of Ohio, haveinvented certain new and useful Improvement in Clearance-CuttingMachinery for Twist- Drills, of which the following is a specification.

My invention has relation to improvements in machines for cutting theclearance of twist-drills; and the object of my invention is to provideimproved mechanism whereby the drill shall be fed with a positivemovement against the cutting Wheel, and firmly and securely held againstsaid wheel until the cutting is completed and which mechanism shall bereadily adjustable to hold the drill at different angles, and providedwith stop mechanism to limit the cut to any desired size of the drill.

To the aforesaid object my invention consists in the peculiar and novelconstruction, arrangement and combination hereinafter described, andthen specifically pointed out in the claims, reference being had to theaccompanying drawings forming a part of this specification.

In the accompanying drawings similar reference numerals indicate likeparts in the several figures.

Figure 1, is a front elevation of my ma chine. Fig. 2, a plan of thesame; Fig. 3, an end elevation of the same; and Fig. 4, a perspectiveview, enlarged, of one of the sleeves hereinafter described.

Referring to the drawings, 1, is a bed, preferably consisting of arectangular form with rounded corners as shown, having on its narroweropposite sides oppositely disposed uprights 2, and on one of theintermediate longer sides a base having a dove-tail slide- Way 3. In theuprights 2, are two sliding bolts 4, arranged to be adjusted and held byset screws 5, and having conical bearings in their inner ends in whichis mounted a shaft 6, by means of adjustable conical end journals 7,which slide in holes in the ends of said shaft and are held by bindingscrews and bearing a grinding wheel 8, preferably of emery, and adriving pulley 9. Mounted on the base and fitting the dove-tailslide-way 3, is a carriage 10, arranged to be moved along saidslide-way, and controlled by a screw 11; which carriage is provided onits upper face with a dove-tail slide-way 12, at a right angle with theslide-way 3. On the latter slide-way 12, is fitted and arranged to slideto and from the wheel 8, a plate 13, having a dependent lip 14, throughwhich passes an adjusting screw 15, arranged to encounter the carriage10, and limit the motion of the plate toward said wheel. On the plate 13is a plate 16, having its inner end pivotally connected therewith by thescrew 17, and its outer end by the screw 18, passing through asegmentalslot into the plate 13, thereby permitting its lateral horizontaladjustment with the axis of the shaft 6. On the plate 16, is a base 19,arranged to slide therein to and from the grinding Wheel 8, andadjustably retained by aset screw 20, passing through a slot into theplate 16. Rigidly attached to the base 19, and preferably integraltherewith is an upright forwardly turned arm 21, arranged to pass beyondthe periphery of the grinding wheel 8, and having in the end adjacent tosaid wheel an opening parallel with the shaft 6, and adapted to receivesleeves of the same external diameter, but of different internaldiameter to fit the diiferent sizes of drills to be ground, one of whichsleeves 28, is shown, enlarged in perspective, in Fig. 1. In the upperfront end and at one side of the arm 21, opposite the wheel 8, is anotch or recess to permit the entrance of the wheel to engage the drillto be cut; and on its curved back a cylindrical boss having a central,vertical hole in which is fitted a post 22, held by a set-screw 23,through the upper end of which' post is a hole transverse to its axis inwhich is inserted a horizontal rod 24, retained by a set-screw 25. Asmall plate, see Fig. 3, is pressed against one side of the end of therod 24, toward the wheel 8, bya set-screw 26; the rod and plateconstituting a clamp which grasps and rigidly holds a steel pin 27,having its lower end rounded fora purpose to be stated. The sleeve 28,is adapted to fit the opening of the arm 21, and has at one side anopening arranged to register with the transverse opening therein topermit the entrance of the wheel 8.

In operation a sleeve 28, of suitable internal diameter to receive thedrill to be cut is placed in the opening of the arm andsecured thereinin any suitable manner, as by. a setscrew, with its transverse openingin alignment with the transverse opening in said arm hereinbeforedescribed. By means of the several adjusting devices hereinbeforedescribed, the arm 21, bearing the sleeve 28, is turned to the angle atwhich it is desired to cut the clearance on the drill. and brought insuch position in front of the wheel 8, that the latter will enter thetransverse openings in said arm and sleeve; and the stop screw 15,adjusted to permit the approach of thedrill to the Wheel 8, to cut thedesired clearance". The pin 27 is then adjusted to enter the v groove inthe drill and simultaneously form an. abutment to resist the-tendency to:rev'olve from ftheattritionof 'the.whee1, and.consti tutea guide tocause the, revolution 'ofi the drill. as it-ismoved horizontally.MOtlOllrbG- in gcommunicated to-' the wheel 8,: a drill-is inserted in.the 'sleeve 28 with the pin 27 resting in its groove the plate 13-isthem-pushed inward bringing'the' drill-in'eontact with the wheel 8, andthe drill isthen moved lengthwise through the-sleeve by hand onceor moreas; maybe necessary to su=fficiently cut the clearance.

a Ilclaim as my invention: 1

1.. In a twist-drill clearance-cutting--ma- 'chine,'thesupportingjframe-and the emery wheel journaled' therein,- and'thehorizontally adjustable carrriage and i thesliding plate mounted onsaidcarriage and arranged to approach and recede fromsaid wheel,. andprovided with an adjustable stop to limit its motion toward said wheel,combined with the upright arm adjustably attached to said sliding,plate,- and... arranged to be rigidly connected and movetherewith, andprovided in its upper end with an opening to receive a Jsleeveto holdthe drill while being ground,

.. neat-ed and move itherewith; and provided in its. upper en dwwith anopenin to' receive a sleeve-to rhold ilhe" drill while being. ground,

and having the adjustable holding mechanismconnected therewithforretaining a guidepinuinv'the drill groove, substantiall y as shownandl described.

In; testimony that I claim the above I here- -u.n to set my-hand.

L OTTO; PARPART.

In presence of 1 O. P. 'I-IUM-PHREY, i HUMPHREY.

